package personal.study.util;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class SetCharacterEncodingFilter implements Filter {
	
	protected String encoding;
	protected FilterConfig filterConfig;
	protected boolean ignore;
	
	public SetCharacterEncodingFilter(){
		this.encoding = null;
		this.filterConfig = null;
		this.ignore = true;
	}

	public void destroy() {
		this.encoding = null;
		this.filterConfig = null;
	}

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		if(this.ignore || request.getCharacterEncoding() == null){
			String encode = selectEncoding(request);
			if(encode != null){
				request.setCharacterEncoding(encode);
			}
		}
		chain.doFilter(request, response);
	}

	public void init(FilterConfig filterConfig) throws ServletException {
		this.filterConfig = filterConfig;
		this.encoding = filterConfig.getInitParameter("encoding");
		String value = filterConfig.getInitParameter("ignore");
		if(value == null){
			this.ignore = true;
		}else if(value.equalsIgnoreCase("true")){
			this.ignore = true;
		}else if(value.equalsIgnoreCase("yes")){
			this.ignore = true;
		}else{
			this.ignore = false;
		}
	}
	
	protected String selectEncoding(ServletRequest request){
		return this.encoding;
	}

}
